How do you calculate the volume/mass of SO2 released from 1m3 Sodium Bisulphite (40%w/w)solution ?

[jus_thom]

The aim is to work out the ventilation requirements for the Sodium Bisulfite (NaHSO3) storage room to ensure COSHH compliance.
From my understanding, the oxidation of NaHSO3 with air results in the formation of SO2.
The vapor cloud above the bisulfite solution is composed of SO2 and H2O.

Available Data
Temperature : 293 K
Vapor Pressure: 4kPa (H2O + SO2)
SO2 Vapor Pressure: 0.9 kPa
Solution Density: 1280 kg/m3
Spillage Volume: 1 m3

Please let me know if any additional info is required.

 

[chicopee]

The American Conference of Governmental Industrial Hygienists (ACGIH) and OSHA would have published acceptable concentrations for either 8 hours work exposure or for short term exposure. Check these references in order to be in compliance. Your main problem would be to determine the generation rate within that work environment.

 

[chicopee]

I am following up on your OP. Do you have a generation rate (mass/ unit of time)of the vapor(h20+SO2) or the amount (weight or mass/unit of time) of NaHSO3 in order to calculate the ventilation requirement? I can easily research the exposure levels acceptable in a work environment using NIOSH or ACGIH data. A perplexing question is that in order to get the reactants (vapor, H2)+SO2) sodium bisulfite has to be mixed with HCl and not air(O2+N2) as you indicated in your OP.

 

[doomster]

The reaction of NaHSO[sub]3[/sub] and air will not result to SO[sub]2[/sub]. If you're talking with SO[sub]2[/sub] generation, probably you are referring to the oxidation reaction of NaHSO[sub]3[/sub] and HCl. In estimating the SO[sub]2[/sub] generated you can use simple stoichiometry for a very rough estimation of the gas generated.